Such devices are known. For instance, one application case of such a device relates to the administering of an infusion solution over a long period of time wherein the infusion solution is to be administered in relatively small amounts over the corresponding period of time. Such a device is also known as an “infusion pump”. It ensures that the infusion liquid, which is, for instance, contained in an infusion bag, is conducted to the body of the patient from the infusion bag by means of a tube system.
From German utility model 295 08 249 a device for administering medicinal liquids is known which has a bellows—like container which is filled with the liquid to be administered. This bellows-like container is inserted into a substantially cylindrical casing which is closed by a cap-like lid engaging over the casing wall. In the lid of the casing a compression spring is located which applies a pressure force to the bellows-like container. The lid and the casing wall cooperate with a screwthread so that the bellows-like container is progressively pressurized with progressing screwing of the lid onto the casing and the liquid contained in the container which is to be administered is dispensed in this manner.
It is a disadvantage of this known device that the lid has to be screwed further with progressive exhaustion of the bellows-like container. Accordingly, the administering process does not occur automatically.